How can I extract the last word from each row of a pyramid?

My function decode() needs to read the text from a .txt file, arrange the number-word pairs in numerical order in the shape of a triangle, and return a string of the last words on each row.

I have successfully arranged the pairs, but when I try to isolate the last words on each row it prints all of the words into the string.

txt_file = ['3 love', '6 computers', '2 dogs', '4 cats', '1 I', '5 you']def decode():    sorted_file = sorted(txt_file)    row = 0    last_words_string = ''    for i in range(len(sorted_file)):        for j in range (0, i + 1):            if row >= len(sorted_file):                break            pairs = sorted_file[row].split()            last_word = pairs[-1]            last_words_string += last_word +''            row += 1            print(pairs, end='')        print()    print(last_words_string)decode()

Here is my current output:

['1', 'I']['2', 'dogs'] ['3', 'love']['4', 'cats'] ['5', 'you'] ['6', 'computers']I dogs love cats you computers

But I need it to say "I love computers".Any ideas what I am missing?